
Re: Countably Infinite Sets
Posted:
Dec 28, 2012 9:08 PM


On Friday, December 28, 2012 6:16:32 AM UTC8, netzweltler wrote: > On 28 Dez., 03:49, "Ross A. Finlayson" <ross.finlay...@gmail.com> > > wrote: > > > On Dec 27, 6:43 pm, netzweltler <reinhard_fisc...@arcor.de> wrote: > > > > > > > Does the set {{1}, {1,2}, {1,2,3}, ...} contain all natural numbers? > > > > > > What does "..." mean? > > > > "..." means, there is a bijection to the natural numbers > > > > 1 > {1} > > 2 > {1,2} > > 3 > {1,2,3} > > ... > > > > > > > > Many would include zero. > > > > I cannot see the difference. I could also have asked: > > Does the set {{0}, {0,1}, {0,1,2}, ...} contain all natural numbers?
You set contains sets that are subsets of all natural numbers. You set contains no natural numbers, only sets.

